The invention relates in general to fuel supply systems for internal combustion engines suitable for use in outboard motors and the like and, more particularly, to a fuel supply system capable of supplying additional fuel both during start-up of the engine and during normal operation to promote acceleration or inhibit engine knocking.
Japanese Laid-Open Patent Application No. 1-313661 discloses an engine for outboard motors and the like provided with a fuel supply system, including a fuel supply increase pump and fuel supply increase control valves that facilitate engine starting by increasing the fuel supply. However, since this conventional system is deactivated by a timer control circuit after the engine has been started and a preset time period has elapsed, it is unable to provide an increased fuel supply for promoting engine acceleration or for preventing engine knocking during normal operation of the engine.
Thus, the invention is directed to the problem of providing an improved fuel supply increase system that is capable of supplying additional fuel not only during start-up of the engine, but also during normal operation to promote acceleration or inhibit engine knocking.